The present disclosure relates to an image forming apparatus.
An electrophotographic image forming apparatus is known. An electrophotographic image forming apparatus typically forms an image on paper by performing processes such as charging, light exposure, development, and transfer.
More specifically, an outer circumferential surface (hereinafter, referred to as an “image bearing surface”) of a photosensitive drum, which is an image bearing member, is uniformly charged to a specific electrical potential of a first polarity (for example, positive polarity) in a charging process. Next, the image bearing surface is exposed to light in a light exposure process so as to form an electrostatic latent image on the image bearing surface. Thereafter, the electrostatic latent image on the image bearing surface is developed in a development process using charged toner. A toner image is formed on the image bearing surface through the development process. In a situation in which development is performed by reversal development, toner charged to the same polarity (first polarity) as the image bearing surface is used.
After the development process, a transfer bias of a second polarity that is opposite to the first polarity is supplied to a transfer roller pressed against the photosensitive drum in a transfer process. The toner image formed on the image bearing surface is transferred onto paper as the paper passes through a pressing part (a nip) between the photosensitive drum and the transfer roller. An image is formed on the paper through the transfer process. After the transfer process, cleaning and static elimination are performed on the image bearing surface before starting a next charging process.
In a situation in which paper is moist in a high-humidity environment, transfer current may leak through the paper to a paper conveyance section disposed around the photosensitive drum. It is known to connect a resistance with the sheet conveyance section in order to restrict leak current from the transfer current.